From: Mimi Zohar <zohar@linux.ibm.com>
To: Matthew Garrett <mjg59@google.com>, Dave Young <dyoung@redhat.com>
Cc: Jiri Bohac <jbohac@suse.cz>,
Linux API <linux-api@vger.kernel.org>,
kexec@lists.infradead.org, James Morris <jmorris@namei.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
David Howells <dhowells@redhat.com>,
LSM List <linux-security-module@vger.kernel.org>,
Andy Lutomirski <luto@kernel.org>
Subject: Re: [PATCH V31 07/25] kexec_file: Restrict at runtime if the kernel is locked down
Date: Mon, 24 Jun 2019 17:27:37 -0400 [thread overview]
Message-ID: <1561411657.4340.70.camel@linux.ibm.com> (raw)
In-Reply-To: <CACdnJusPtYLdg7ZPhBo=Y5EsBz6B+5M2zYscBrLcc89oNnPkdQ@mail.gmail.com>
Hi Matthew,
On Mon, 2019-06-24 at 14:06 -0700, Matthew Garrett wrote:
> On Sun, Jun 23, 2019 at 6:52 PM Dave Young <dyoung@redhat.com> wrote:
> >
> > On 06/21/19 at 01:18pm, Matthew Garrett wrote:
> > > I don't think so - we want it to be possible to load images if they
> > > have a valid signature.
> >
> > I know it works like this way because of the previous patch. But from
> > the patch log "When KEXEC_SIG is not enabled, kernel should not load
> > images", it is simple to check it early for !IS_ENABLED(CONFIG_KEXEC_SIG) &&
> > kernel_is_locked_down(reason, LOCKDOWN_INTEGRITY) instead of depending
> > on the late code to verify signature. In that way, easier to
> > understand the logic, no?
>
> But that combination doesn't enforce signature validation? We can't
> depend on !IS_ENABLED(CONFIG_KEXEC_SIG_FORCE) because then it'll
> enforce signature validation even if lockdown is disabled.
I agree with Dave. There should be a stub lockdown function to
prevent enforcing lockdown when it isn't enabled.
Mimi
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next prev parent reply other threads:[~2019-06-24 21:27 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20190326182742.16950-1-matthewgarrett@google.com>
2019-03-26 18:27 ` [PATCH V31 04/25] kexec_load: Disable at runtime if the kernel is locked down Matthew Garrett
2019-03-26 18:27 ` [PATCH V31 05/25] Copy secure_boot flag in boot params across kexec reboot Matthew Garrett
2019-03-26 18:27 ` [PATCH V31 06/25] kexec_file: split KEXEC_VERIFY_SIG into KEXEC_SIG and KEXEC_SIG_FORCE Matthew Garrett
2019-06-21 6:34 ` Dave Young
2019-06-21 20:13 ` Matthew Garrett
2019-06-21 20:14 ` Matthew Garrett
2019-03-26 18:27 ` [PATCH V31 07/25] kexec_file: Restrict at runtime if the kernel is locked down Matthew Garrett
2019-06-21 6:43 ` Dave Young
2019-06-21 20:18 ` Matthew Garrett
2019-06-24 1:52 ` Dave Young
2019-06-24 21:06 ` Matthew Garrett
2019-06-24 21:27 ` Mimi Zohar [this message]
2019-06-25 0:02 ` Matthew Garrett
2019-06-25 1:46 ` Mimi Zohar
2019-06-25 2:51 ` Dave Young
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